2025 City of Manteca Public Health Goals ReportFebruary 17, 2026
Background
The City monitors water quality to ensure compliance with all state and federal drinking water standards Every three years, California law requires the City to report on any constituents that exceeded Public Health Goals in the prior three years
Public Health Goals
PHGs are not regulatory standards
Non-enforceable, health-based goals to help water systems monitor constituents of interest Established by California Office of Environmental Health Hazard Assessment For some constituents:
Current laboratory methods cannot reliably detect it at PHG levels Treatment does not currently exist to get to PHG levels Treatment may exist, but the cost may be very high
Drinking Water Sources
15 active groundwater wells
Treated surface water purchased from South San Joaquin Irrigation District
2022-2024 Monitoring Results
7 constituents detected above their PHG in some groundwater wells All constituents were below drinking water standards except 1,2,3 trichloropropane (TCP), which was detected above the allowable limit at a single groundwater well TCP has been regulated since 2018
The City began mitigating for TCP in 2014
Following the TCP detection, the City reduced water production from affected wells
2022-2024 Monitoring Results
Detected Constituents above PHGs
Arsenic
Chromium VI (hexavalent chromium)
1,2,3 Trichloropropane (TCP)
1,2-Dibromo-3-chloropropane (DBCP)
Tetrachloroethylene (PCE)
Gross Alpha
Uranium
Any health concerns associated with constituents are listed in the PHG Report Some constituents are naturally occurring in groundwater
Next Steps
Health benefits of installing treatment would be uncertain since some PHGs are set below what laboratories can reliably measure Installing additional treatment would result in high additional costs to ratepayers The City’s drinking water meets all state and federal safety standards Water quality will continue to be a very high priority for the City and closely monitored and publicly reported
Questions?